Conventionally, there have been various technologies developed for improving the quality of a video.
Patent Literature 1 discloses a luminance conversion device developed with the aim of properly highlighting contrast of even a person whose image is captured in front of a wall surface of a building, which wall surface has little luminance variation. The luminance conversion device of Patent Literature 1 is configured to (i) obtain (a) a luminance histogram indicative of the respective numbers of pixels of input images in different luminances and (b) an edge histogram indicative of the respective numbers of edges in the different luminances and (ii) convert the luminance of an input image by use of the two histograms.
There has also been a technology developed for reducing noise that occurs in the process of decoding a video which has been compression-encoded.
For example, in many cases, an image compressed with a compression-encoding system such as MPEG or JPEG that is high in compressibility has edges around which mosquito noise is generated. The occurrence of mosquito noise, which is a cause for deterioration of image quality, can be reduced by a smoothing process.